Staging is the process of finding out how much cancer is in a person’s body and where it’s located. It’s how the doctor determines the stage of a person’s cancer.
Staging information is used to help plan treatment and predict a person’s prognosis. Bearing in mind we are all different, cancers with the same stage do tend to have similar outlooks and are often treated in the same way.
One of the tools specialists use to describe the stage is the TNM system. Using the results from your diagnostic tests and scans, specialists can use TNM to develop a shorthand description of your cancer.
In the TNM system, each cancer is assigned a letter or number to describe the tumor, node, and metastases.
- T stands for the original (primary) tumour.
- N stands for nodes. It tells whether the cancer has spread to the nearby lymph nodes.
- M stands for metastasis. It tells whether the cancer has spread to other parts of the body.
The T category provides information about the original (primary) tumour, such as size, how deeply it has grown into the organ it started in, and whether it has grown into nearby tissues.
- TX means the tumour can’t be measured.
- T0 means there is no evidence of a primary tumour (it cannot be found).
- Tis means that the cancer cells are only growing in the most superficial layer of tissue, without growing into deeper tissues. This may also be called in situ cancer or pre-cancer.
- Numbers after the T (such as T1, T2, T3, and T4) might describe the tumour size and/or amount of spread into nearby structures. The higher the T number, the larger the tumour and/or the more it has grown into nearby tissues.